164 AN IRISH SALMON-RIVER 



(Lagopus alba), sold as ' ptarmigan ' by our poulterers in 

 spring, possesses no anatomical distinction from the 

 British red grouse (L. scotica) ; the human ear can dis- 

 tinguish no difference in the voice of the two species; 

 their eggs are identical in shape and colour ; the summer 

 plumage of the first has a strong resemblance to the year- 

 round jacket of the second ; the sole reason for classifying 

 these birds as distinct species being that the willow- 

 grouse turns white in winter, which the red grouse does 

 not. But a precisely similar seasonal variation in the 

 colour of the common stoat has not brought about the 

 recognition of two species. In the northern parts of 

 Britain this animal regularly assumes the ermine livery 

 in winter, in the southern counties it remains russet all 

 the year through ; but the specific identity of the two 

 forms is established by the partial change which takes 

 place in the intermediate region, where the little creature 

 appears in winter with a piebald coat of white and brown. 

 Peradventure some will bear to be reminded that the 

 humble British stoat (Putorius erminea) is none other 

 than the animal which, in more rigorous climes than ours, 

 produces ermine fur, so highly prized in days of chivalry 

 that it was reserved under statute for the exclusive wear 

 of royal persons. 



It is obvious, then, that men of science are not yet 

 agreed upon a thoroughly satisfactory system of classifica- 

 tion ; and that if the tendency to subdivision be indulged 

 further, it will be difficult to refrain from applying it to 

 the human race. Of such slender consistency ran the 

 thread of my meditation lately, while casting angle more 

 or less ineffectively more rather than less upon what is 

 naturally one of the finest salmon-rivers of Ireland. 



